Materials:1/2" plywood
circular saw
wood glue
nail gun (or hammer/nails)
large square
pencil
1" cleats
1/2" quarter round molding
1x2, 1x3 and 1x4 poplar lumber
jigsaw with scroll blade
hinges and hardware
tape measure
wood filler
sandpaper
primer and paint or stain
Steps:
1. Measure the corner of the bathroom where the cabinet will be placed to get the desired dimensions. The featured project's one side is 18 inches wide and the other is 18-1/2 inches wide (when attached together, each side will be 18-1/2 inches due to the plywood's thickness).
2. Since the piece is angled, the sides and cleats need to be mitered at the front so the front facing will lay flush. Set the circular saw at a 45-degree angle and cut the plywood sides using a guide to keep the saw straight. Cut the cleats to size, being sure to miter the front ends.
3. Lay the sides next to each other on a flat surface. Use a large square to draw lines across both boards to mark where the one-inch cleats will hold up the shelves. Run a bead of glue along the cleats and nail each in place.
4. Assemble the two sides together using a butt joint, wood glue and nails.
5. Measure the inside of the cabinet from outer corner to outer corner and cut the shelves to size using a circular saw. Tip: When cutting plywood with a circular saw, cut with the finish (good) side down so chips don't ruin the exposed surface.
6. Install the shelves to the inside of the cabinet by nailing each into the cleats and dress-up the inside top edge using 1/2-inch quarter round.